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Soyuz rocket to launch the Aist-2T pair, Iranian satellites A Soyuz-2-1b/Fregat rocket is scheduled to close Russia's orbital launch attempts in 2025 with a mission to deliver a pair of Aist-2T Earth imagers and 50 hitchhiking payloads, including a trio of Iranian satellites, on December 28.
Aist-2T mission at a glance:
The dual-purpose Aist-2T satellite with a mass of 670 kilograms, was developed at RKTs Progress in Samara under a 2019 contract with the Roskosmos State Corporation, which ordered a two-spacecraft system producing stereo-imaging of the Earth surface from a Sun-synchronous orbit. The stereo imagery would be possible thanks to a dual set of cameras on each Aist-2T (instead of one on the previous-generation Aist-2D, launched in 2016, making it possible to photograph each area under a slightly different angle. The Aist-2T satellite was reported to be capable of capturing images with a resolution as high as 1.6 meters, when photographing in nadir (directly below its flight path) in pan-chromatic mode. In the same imaging mode, it could also produce stereo images with a resolution up to 1.9 meters. Multi-spectral and color imagery was reported to be possible with a resolution of 4.8 meters when pointing in nadir or up to 5.9 meters for stereo sets of photos. The Aist-2T variant also featured a built-in propulsion system for the first time, while the satellite's downlink channel for sending imaging data back to Earth was expanded from 150 megabits per second on Aist-2D to 1,600 megabits per second on the 2T version. As of February 2020, the Aist-2T pair was scheduled for launch in November 2022, but by 2021, it slipped to 2023 and was later re-scheduled for Dec. 25, 2024. By mid-October 2024, the mission was postponed again, until at least March 17, 2025, and by the end of 2024, it was rumored to be delayed until June 26, 2025. Early in 2025, the launch slipped to the end of August 2025 and, ultimately to December of the same year. Secondary payloads
In addition to the launch of the Aist-2T pair, the same Soyuz-2-1b rocket was also booked to carry 50 dual-purpose secondary payloads, ranging from light-weight experimental satellites down to an assortment of educational cubesats and a small carrier platform, itself designed to release the tiniest satellites known as pikosats. A total of 33 payloads were to be deployed from 17 launch containers provided by Moscow-based Aerospeis Kapital. The most notable secondary payloads on the mission were two Marafon-IoT experimental satellites (INSIDER CONTENT), developed at ISS Reshetnev and intended for paving the way to the so-called Internet-of-Things satellite system, however, by the time they reached the launch pad, the main project was facing cancellation due shrinking Russian space budget. The most significant foreign payload on the Aist-2T mission was a trio of Iranian dual-purpose satellites all intended for remote-sensing of the Earth's surface. Other small foreign payloads were ordered by various institutions in Montenegro, Kuwait, Qatar, Ecuador and Belarus. Also, the St. Petersburg-based STTs government-supported center reported sending a total of eight small payloads on the Aist-2T mission. The payload fairing of the rocket also carried a logo of the Pixidex company from South Africa, which specialized in equipment for suppressing drones, but it was not immediately clear which satellite carried its payload. Payloads aboard the Soyuz launch on Dec. 28, 2025:
Launch campaign
The Soyuz launch vehicle for the Aist-2T mission was delivered by rail from Samara to Vostochny in mid-November 2024. On Oct. 31, 2025, Roskosmos announced the start of work with the Fregat upper stage for the Aist-2T mission in Vostochny. The space tug was extracted from its transport container and placed at its work site inside the spacecraft processing building for upcoming pneumatic and electric tests. Upon their completion, the stage was to be ready for delivery to the fueling station, ZNS, for propellant and pressurized gases loading, which would represent irreversible operations and kick off the active launch campaign, but at the time, Roskosmos did not mention the launch date for the mission. According to unofficial sources, by early November 2025, the industry committed to launching the mission on Dec. 28, 2025. The electric and pneumatic-vacuum tests of the Fregat upper stage were completed by Nov. 20, 2025, and the space tug was reported sent to fueling with propellant and pressurized gases. The critical meeting of the State Commission overseeing the launch was scheduled for Dec. 5, 2025, and it apparently confirmed the readiness of the mission for Dec. 28, 2025, launch. On Dec. 8, 2025, Roskosmos reported ongoing assembly of booster stages for the Soyuz-2.1b rocket, secondary payloads and the main payload section for the mission in Vostochny. The state corporation also confirmed the completion of Fregat fueling operations but still did not mention the planned launch date for the mission. The integration of the four boosters of the first stage with the core booster of the second stage was reported completed on Dec. 11, 2025. An Il-76 transport aircraft with a pair of Aist satellites landed at Vostochny's airport on Dec. 15, 2025. By Dec. 23, 2025, the assembly of the payload section was completed and it was encapsulated under the 81KS payload fairing of the Soyuz rocket. The next day, the payload section was transferred to the Vehicle Assembly Building, MIK RN, where it was integrated with the third stage of the Soyuz launch vehicle, which in turn was connected to the booster stages of the rocket, completing the assembly of the vehicle. The next day, the State Commission overseeing the launch cleared the vehicle for the rollout to the launch pad, which proceeded as planned on the morning local time in Vostochny on Dec. 26, 2025. Launch profile 
A Soyuz-2.1b rocket carrying the Aist-2T pair and secondary payloads is scheduled to lift off from Site 1S in Vostochny on Dec. 28, 2025, at 16:18 Moscow Time (8:18 a.m. EST). After a few seconds of vertical ascent under the power of the four boosters of the first stage and the core booster of the second stage, the rocket will head northwest across eastern Russia, aligning its trajectory with a near-polar orbit inclined around 98.57 degrees toward the Equator and an azimuth of 344.13 degrees. The strap-on boosters of the first stage should separate 1 minute 59 seconds after liftoff in order to crash at Drop Zone No. 981 in the Amurskaya Oblast (Amur Region) on the border between the Tynda and Zeya Districts. The fairing protecting the payload will then split in two halves and separate during the operation of the second stage at 3 minutes 46 seconds in flight. As a result, the payload fairing fragments should fall at Drop Zone No. 983 in the Aldan District in the Sakha (Yakut) Republic. Moments before the second stage completes its firing 4 minutes and 47 seconds into the flight, the RD-0124 engine of the third stage will begin to fire through the inter-stage lattice structure, which moments later should separate along with the second stage 4 minutes and 48 seconds after liftoff. Just 1.5 seconds later, the tail section on the third stage will split into three segments. Both, the second-stage booster and the segments of the tail section should impact the ground at Drop Zone No. 985, in the Vilyusk District, located farther north in the Sakha Republic. The third stage will continue firing, inserting the Fregat upper stage and its passengers into an orbit with an apogee (highest point) of 196 kilometers and a perigee of just 12 kilometers or well in the dense atmosphere. As a result, after its engine cutoff and separation from Fregat, 9 minutes 24 seconds after liftoff, the third stage will begin a long free fall back to Earth over the Arctic and Northern Atlantic Oceans. Its trajectory is designed to bring the flaming debris of the booster crashing into the Atlantic Ocean. Space tug flight profile Following its split from the third stage, the Fregat is usually programmed to fire its engine over the Arctic Region 10 minutes 24 seconds after liftoff for around 1.5 minutes to ensure its insertion into a transfer orbit. The six-ton stack will then climb passively for around 46 minutes before Fregat has to fire for the second time near the apogee of its initial orbit, this time over the Antarctica, around 57 minutes 44 seconds after liftoff. The maneuver, lasting less than a minute, should insert the vehicle into a nearly circular orbit around 830 kilometers above the Earth's surface. Around a minute later, the primary payload, in this case a pair of Aist-2T satellites, is usually programmed to eject from Fregat's payload adapter, completing the main task of the mission. Because the initial engine firings are performed by the Fregat beyond the view of Russian ground stations, their successful completion has to be confirmed during the subsequent passes of the vehicle over Russia. After the successful release of its primary payload, the Fregat embarks on a pre-programmed sequence to deliver its secondary payloads into their orbits, which starts with the third firing of the main engine to enter a transfer orbit. The separation orbit is usually formed with the fourth maneuver. After the release of its final passenger around five hours after its liftoff from Vostochny, the Fregat is expected to conduct another pre-programmed maneuver to place itself on a reentry trajectory into the Earth's atmosphere and disintegrate over the Equatorial region in the eastern section of the Pacific Ocean.
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